This project was designed to investigate the response of plant growth and reproduction to short- and long-term variation in biotic and abiotic environmental variables. Several perennial taxa, including tree (Juniperus monsperma and Pinus edulis), shrub (Larrea tridentata) and bunch grasses (Oryzopsis hymenoides (now Achnaterum hymenoides) and Sporobolus contractus) species, were monitored at 1-3 sites differing in elevation and topography as well as edaphic variables and annual precipitation. The sites represented optimal or marginal/transitional zones for particular species. Demographic measurements were made biannually, after the 'wet' (fall) and 'dry' (spring) seasons. For tree and shrub species, estimates of growth and reproduction were based on branch demography, with ten branch tips from 10-20 individuals per species per site repeatedly measured from 1989-1993. For J. monsperma, P. edulis and L. tridentata, vegetative growth (i.e., branch growth) as well as reproduction were monitored. Additional measurements included needle length for P. edulis and leaf production, leaf size and branchlet production for L. tridentata. For grasses, basal diameter, leaf length and reproduction were monitored for 100 individuals per species per site.
Pinon-juniper plant dimension data was collected to obtain a measure of the change in the size of individual pinon and juniper trees through time. This data encompasses growth over 11 years and was to be used in conjunction with data in the Sevilleta plant demography and plant physiology data bases. However, those studies were discontinued in 1993.
This project, SEV025, contains only data on pinon-juniper plant dimensions. Data on other variables and species is contained in SEV006, SEV024, SEV026, SEV027, and SEV028.
Data was collected on the Sevilleta National Wildlife Refuge in Soccoro County, central New Mexico. The Sevilleta encompasses almost 100,000 ha of land that has floristic influences from the Chihuahuan Desert to the south, the Great Plains grassland to the east, the Great Basin Desert to the northwest, and montane vegetation as elevation increases.
Goat Draw - This site is located in a small canyon that drains the Los Pinos to the east and is dominated by pinon/juniper woodland with occurrences of Quercus turbinella, Yucca spp., and Opuntia spp. This small canyon drains into the channel known as Goat Draw. This site contains two study sites, each with 49 tagges trees. The tagged and measured trees are distributed nearly equally on slopes on either side of the small canyon.Sepultura Flats - This area slopes to the south from the north rim of Sepultura Canyon. Juniper woodland near the rim grades into blue/black grama grassland mixed with a few woody species such as snakeweed (Gutierrezia sarothrae) downslope. The measured trees are on the rim of Sepultura Canyon and the rocky slopes at the east edge of Sepultura Flats. This study site was discontinued in 1990 and all tags removed from the trees.
Data was collected on one-seed juniper (Juniperus monosperma), and pinon pine (Pinus edulis). Trees were sampled in 1989 and 1993 to measure growth. A subsample of trees was measured again in 1999. Only trees in the low portion of Goat Draw on the southeast-facing slope were measured in 1989 as time constraints prevented the measurement of other trees.
Bole circumference - The circumference at the base of a tree. If a pinon was multiple-boled, the circumference of each bole that supported live growth and was greater than 10cm in circumference was added. (For junipers each bole was added to get total circumference.) Circumference was measured at ground level, but some boles were not perpendicular to the ground. In such cases, the circumference was taken on a cross-section perpendicular to the axis of the bole, and the tape wrapped around the bole so that it touched ground at some point. This measurement was recorded as cab1......cab15.
Height - The height of the tree from ground level to the uppermost live branch of the tree.
Length - This is a measure of the diameter of the tree crown atits widest point. The tape was stretched alongside the tree parallelto its widest point and the length taken from the outermost branches.
Width - This width measurement was taken in 1989 and 1999. This was the width of the tree crown measured perpendicular to the length measurement, a measure of the crown at its widest point.
Stream side - This is the width as measured in 1993 (and also 1999). The tape was stretched alongside the tree parallel to the main channel of GoatDraw, and the width taken from the outermost branches.
Angle - Taken by standing at a measured distance (see distance measurement description) from a tree and using a clinometer to determine the angle from the ground to the top of the tree. The height of the person using the clinometer was considered to correctly calculate tree height. Alethea Banar read the clinometer and her height was 1.54 meters.
Distance - This is the distance from the observer to the tree at which the angle measurement was taken.
Data was collected on 27 Jun 1989 at Goat Draw: Junipers #1 - #50 and #7 Goat Draw: Pinyons #1 - #50. Data was collected on 29 Jun 1989 at Sepultura Flats: Junipers #1 - 50#. Data was collected on 5 Oct 1993 at Goat Draw: Junipers #14 - #25 and Goat Draw: Pinyons #14 - #25. Data was collected on 6 Oct 1993 at Goat Draw: Junipers #1 - #13, #15 - #50 (except for #44 & #6) and Goat Draw: Pinyons #1 - #13, #15 - #50 (except for #44). Data was collected on 11 Oct 1993 at Goat Draw: Juniper 44 and Pinyon 44. Data was collected on Nov 16, 1999.
The data was collected under the supervision of Theresa Newberry, along with David Keller and Alethea Banar. The data was entered by Rupal Shah on 19 Jan 1993. The metadata was entered by Troy Maddux after some conversation with Theresa Newberry on 18 - 19 Feb 1993.
Data from 1993 was collected under the supervision of Marilyn Altenbach along with Troy Maddux, Eric Scherff, and Nina King on 5, 6 and 11 October 1993. The data was entered by Eric Scherff and Marilyn Altenbach on 7 October 1993 and Marilyn Altenbach on 11 October 1993.
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